a. Field of the Invention
The present invention relates to wheelchairs and, in particular, to a locking mechanism to lock a footrest hanger onto a wheelchair side frame.
b. Prior Art
The typical wheelchair is provided with footrest hangers that extend downwardly in front of the wheelchair from respective wheelchair side frames for the purpose of supporting the footrests. When the user sits in the wheelchair, a footrest provides support for the user's feet. The typical footrest hanger has an upper portion that extends out of the wheelchair side frame and which then curves into a substantially straight downwardly-extending portion that leads to the footrest. The hanger is typically removably locked onto the side frame, but the lock is releasable so that the hanger can be taken off.
Prior art approaches to locking the hanger into position on the wheelchair have drawbacks. One approach is to mount a spring loaded pin in the interior of a portion of the side frame. The side frame is typically tubular with a hollow area inside. The hanger is provided with a downwardly extending portion having an indentation that is compatible with the spring-loaded pin in the side frame tube. As the downwardly extending portion of the hanger is inserted into the tube, the pin engages with the indentation, thereby locking the hanger into place on the frame. A recurring problem with this arrangement is that when the user puts his or her foot down onto the footrest, the user's foot pushes the hanger downwardly, thereby disengaging the hanger from the engagement with the engagement pin. The hanger is then free to rotate from side to side and can easily become disengaged from the side frame.
Another approach is to provide the side frame with an upwardly-extending pin having a wide head. The hanger is then provided with a bracket having an opening to receive the wide head, and a relatively narrower slot adjacent thereto for engaging the wide head. The user typically rotates the hanger after the head has been inserted into the head-receiving opening in order to lock the hanger into place. A problem with this approach is that it is cumbersome for the user and is hard to use.
What is needed, then, is an improved locking mechanism for a wheelchair footrest hanger that will securely hold the hanger in place on the side frame and that is convenient to use.